Glass, and in particular chemically strengthened glass, has become the material of choice for the view screen of many, if not most, consumer electronic products. For example, chemically strengthened glass is particularly favored for “touch” screen products whether they be small items such as cell phones, music players, eBook readers and electronic notepads, or larger items such as computers, automatic teller machines, airport self-check-in machines and other similar electronic items. Many of these items require the application of antireflective (“AR”) coatings on the glass in order to reduce the reflection of visible light from the glass and thereby improve contrast and readability, for example, when the device is used in direct sunlight. However, some of the drawbacks of an AR coating are its sensitivity to surface contamination and its poor anti-scratch durability, that is, the AR coating becomes easily scratched during use, for example, by a wiping cloth or the dirt and grime on a user's finger. Fingerprints and stains are very noticeable on an AR coated surface and are not always easily removed. As a result, it is highly desirable that the glass surface of any touch device be easy to clean which is achieved by applying an easy-to-clean (ETC) coating to the glass surface.
The current processes for making glass articles having both antireflection and ETC coatings requires that the coating be applied using different equipment, and consequently separate manufacturing runs. The basic procedure is to apply the antireflection (“AR”) coating to a glass article using, for example, a chemical vapor (“CVD”) or physical vapor deposition (“PVD”) method. In conventional processes, an optically coated article, for example, one with an AR coating, will be transferred from the optical coating apparatus to another apparatus to apply the ETC coating on top of the AR coating. While these processes can produce articles that have both an AR and an ETC coating, they require separate runs and have higher yield losses due to the extra handling that is required. This may result in poor reliability of the final product due to contamination arising from the extra handling between the AR coating and ETC coating procedures. For example, using the conventional 2-step coating process of ETC over an optical coating results in an article that is easily scratched in touch screen applications. In addition, while the AR coated surface can be cleaned before applying the ETC coating, this involves additional steps in the manufacturing process. All the additional steps increase the product costs. Consequently, alternative methods and apparatuses are needed by which both coatings can be applied using the same basic procedure and equipment, thus reducing manufacturing costs. Advantages of the process disclosed herein and resulting products are set forth in the following paragraphs and claims.